TEMPERATURE CONTROLLER FOR HEATING COOKER

摘要

PURPOSE:To control quickly the temperature to a prescribed level in a simple constitution by using a detector containing a feedback line where the negative feedback quantity is larger than the positive feedback quantity in terms of DC and vice versa in terms of AC respectively. CONSTITUTION:A switch circuit 2 supplies the electric power to a heater 1 for an object to be heated, and the temperature of the objective to be heated is detected by a temperature detecting element 3. When the temperature of the object approximates to a prescribed level, the non-inverted input voltage b1 is lower than or equal to the inverted input voltage b2. Thus a detector 6 delivers an output ''L'' to turn off the circuit 2, and the temperature of the object starts to drop with a time delay. In this case, no time delay is produced at the non-inverted input side and the opposite input side has a delay by an amount equal to the discharge time of a capacitor 63. The AC component produced from said delay has a large positive feedback quantity, and therefore the voltage b2 is varied down to a level lower than the voltage b1. Then the output of the detector 6 is inverted with b2<=b1 and set at ''H''. Thus the detector 6 contains a feedback line where the negative feedback quantity and the positive feedback quantity are large in terms of DC and AC respectively.